HERBACEOUS FLORA OF FORESTS AND FIELDS. 63 



pubescent beneath, the berries in compact rather oval clusters, pur- 

 plish black without bloom, juicy, and sweet, ripening in the latter 

 part of September. Robwia kispida and Rosa kumilis are common 

 on these rocks. Amorpha virgata and Viburnum accri/olium prefer 

 slight declivities with a dry but somewhat less rocky soil. Among 

 the other xerophile rupestrian associations, on the summit of Che- 

 hawhaw Mountain rock-tripe, a large lichen (Umbilicaria), covers 

 with its black thalloid frond the bare crags, and forms a striking 

 feature; it has also been observed to cover the rocks on the crest of 

 Lookout Mountain (De Kalb County, 1,800 to 2,000 feet altitude), 

 and is characteristic of the southeastern Alleghany ranges north to 

 Pennsylvania. Of the few ferns frequenting these arid heights, 

 Cheilanthes tomentosa is the most common. The long stipes of the 

 fronds lie deeply buried among the smaller fragments of the rocks, 

 where the fibrous roots, protected from the sun, find the needed 

 supply of moisture. Dryopteris marginalis is rarely found in the 

 sheltered rocky clefts. The coarse Andropogoneae, already named, 

 under the scanty shade of mountain oaks, chestnuts, and pignut hick- 

 ory, completely hide the ground with their luxuriant growth. The 

 fine tufts of StenophyUw capillaris, with Talinum teretifolium, cover 

 the flat expanses of the rocks, bare of any other vegetation. Silene 

 stellata and Anychia dichotoma prefer the shaded rocky shelves. Stei- 

 ronema tonsum, through the abundance of its bright golden flowers, 

 is the most conspicuous among the herbs. This ornament of the cliffs, 

 extending northward to the mountains of Kentucky, has also been 

 observed on the open hills of the Delta divide (Clay County, altitude 

 1,600 feet). Ladnaria graminifolia, in dense tufts formed by its 

 confluent tuberous root-stocks, covers the sunny rocks throughout this 

 subdivision, while the following, more or less common throughout the 

 southern extent of the Appalachian chain, are frequently met with in 

 open rocky woodlands: 



Campanula divaricata. Solidago erecta. 



Dasystoma flava. Brachychaeta sphacelata. 



Solidago bicolor. Gerardia tenuifolia asperula. 



Wherever the ridges spread out into wider expansions forming 

 broad uplands, now denuded of their original forest growth and mostly 

 subjected to cultivation, a xerophile campestrian flora has taken pos- 

 session, with Compositae as its prominent feature. Such plains extend 

 through the metamorphic region of South Carolina and Georgia to 

 its southern limit in Alabama, with an elevation of from 1,600 feet 

 (Clay County, about Delta) and 1,200 feet (Cleburne County, Chula- 

 finnee) down to 860 feet in Lee County (Auburn). The borders of 

 fields and woods, meadows and pastures, appear to be emphatically 



